This invention relates to stringed musical instruments, and more particularly to apparatus for varying the tension in one or more of the strings and for tuning the strings of a stringed instrument of the type providing selective increases and decreases in the tension or tone of individual strings of the instrument, such as a steel guitar.
Playing a steel guitar is a relatively involved task. The instrument is played by moving a metal bar or "steel" along the strings to vary their effective length while plucking certain strings to produce the desired tone or chord. Variations of this technique are common to playing most stringed instruments, but additionally, with steel guitars the tension of one or more of the strings may be selectively increased or decreased from a normal level. Tension changes are controlled through foot pedals or knee pedals which the musician selectively operates singularly or in combination to achieve the different tensions or pitches from tone to tone and chord to chord throughout a musical composition. To play the instrument correctly, the musician must remember the manner in which the tension of one or more of the strings is changed by depression of each of the foot and knee pedals while moving the steel to vary the effective length of the string and choosing the correct string or strings to pluck. Although difficult to master and complicated to play, a skilled musician can produce a unique and interesting variety of sounds from a steel guitar, which partially accounts for the popularity of the instrument in certain musical groups.
It can readily be understood that apparatus for a stringed instrument of the steel guitar type which simplifies the tasks required of the musician and enhances the skill of the musician is of significant importance, and it is a general objective of this invention to provide such apparatus. Other objectives of this invention relate to improving the control over the tone changes produced by operation of the pedals, the ease by which the pedals may be operated, the arrangement of the apparatus to secure the tone changes desired, the tuning of the tone when the tension in a string is varied, and the assembly of the instrument.
The invention itself involves, in one embodiment, transforming means in a tone changer of the type having a pivotable member connected to each string for varying the string tension when pivoted as a result of rotation of a bar member operatively connected to the pivotable member. An actuator means and other associated apparatus selectively operated by the musician operatively causes rotation of the bar member, and operatively interposed between the actuator means and the bar member to secure one condition of rotation of the bar member is the transforming means for transforming an amount of translational movement of the actuator means to a different or lesser amount of movement applied to rotate the bar member. The transforming means may also apply a greater force on the bar member than that force applied by the actuator means, apply an increasing incremental movement to the bar member in relation to increasing movement of the actuator means, and cause the approximate same increase in tension as a resulting decrease in tension for approximately the same amounts of movement of the actuator means. A translational movement means includes means for supplying approximately equal amounts of movement for use by the control rods connected with the actuator means for increasing and for decreasing the tension of the strings. A tuner transfers movement from the translational movement means to the control rod and is used for fine tuning the tone or tension change. The tuner may comprise two stop members and a means for resisting relative movement between the control rod and one stop member whereby the stop members are prevented from moving due to naturally occurring forces. The tuner may also include means for holding one of the stop members or preventing relative rotational movement of one of the stop members when fine tuning the amount of tone or tension change.
A more complete description of one embodiment of the invention and its objects and advantages may be found in the following detailed description of the invention and brief description of the drawings.